Thought Leadership

Protect your premium inventory with Ads.txt

October 3, 2017

By John Clyman

Ad fraud remains a huge problem for online advertising, with estimated losses expected to reach $6.5 billion globally in 20171. Yet there’s a simple initiative that is combatting this kind of abuse and helps to ensure sellers are getting the spend that’s intended for them and buyers’ dollars aren’t being siphoned away. That initiative is Authorized Digital Sellers, better known as Ads.txt — and the time to adopt it is now.

What is Ads.txt?

Ads.txt is a simple way for publishers to declare which parties are authorized to sell their inventory. Established by the IAB Tech Lab, Ads.txt fights inventory fraud and helps to reduce counterfeiting, making the advertising ecosystem safer and more transparent for everyone involved.

Today, it’s hard for most buyers to know whether they’re buying authentic inventory from a legitimate source. With ads.txt, sellers create URLs on their sites that list which parties are allowed to sell their inventory. Buyers can consult this information to ensure they’re purchasing from an authorized source. This transparency can be a boon to the entire media and marketing ecosystem.

Why should you add ads.txt to your sites?

Without ads.txt, bad actors can sell your inventory without authorization, or spoof a domain to line their own pockets instead of yours. While the Rubicon Project platform employs mechanisms to hinder spoofing, chances are you work with multiple partners to monetize your sites — so the best way to ensure that every potential buyer has complete, accurate, up-to-date information is to employ ads.txt.

What’s more, buyers are starting to signal they’ll use ads.txt to direct their spending decisions as early as Q4 of 2017. For example, Google’s DBM (Doubleclick Bid Manager) DSP announced publicly that it will reject bids that violate published ads.txt directives by the end of October, and that it expects to stop buying on sites that lack ads.txt files at an unspecified future date. Based on our discussions with other key industry participants, we expect ads.txt adoption by sellers to accelerate through the end of this year and become widespread in Q1 of 2018, with enforcement by buyers trickling out soon and extending into 2018.

The best outcome for the industry will be if every seller publishes an ads.txt file and every buyer and exchange enforces published ads.txt guidelines.

What should I, as a seller, do to support ads.txt?

Since ads.txt is just a simple text file, it should be easy for site owners to start working with their product or development teams to publish ads.txt for their sites. Be sure to only include trusted partners in a published ads.txt — we’ve heard reports of social engineering attempts by shady parties that may be reselling inventory without authorization and claim your monetization will suffer if you exclude them.

If you’re an inventory aggregator, you should have each site you work with authorize the resale of their inventory via the Rubicon Project platform in each site’s ads.txt file. In this case, where Rubicon Project has an indirect relationship with the site owner, it’s crucial that ads.txt indicates not just that Rubicon Project can sell the site’s inventory, but that we can sell it specifically through your account(as opposed to, or in addition to, through some other partner). This will verify the inventory is yours to sell through our marketplace.

If your business is a mobile app, you can hold off for now, as ads.txt does not currently support mobile app inventory — though the IAB Tech Lab is working to add this in future versions of the spec.

What will buyers do with ads.txt?

To avoid buying unauthorized or counterfeit inventory, DSPs should reject bid requests from sources not listed in an ads.txt file when ads.txt is present. At some point, DSPs may allow individual buyers to reject inventory from sites that haven’t published ads.txt files.

Advertisers and agencies should insist their DSPs reject bid requests from sources not listed in an ads.txt file when ads.txt is present. And some of these buyers may go further, and choose only to buy on inventory that is affirmatively verified via the presence of an ads.txt file.

How does ads.txt work?

Ads.txt creates a publicly accessible record of authorized digital sellers for publisher inventory. Programmatic buyers can then capture this data and reference it when bidding if they wish to purchase inventory from authorized sellers.

Participating publishers post their list of authorized sellers to their domain.

Programmatic buyers crawl the web for publisher ads.txt files to create a list of authorized sellers for each participating publisher.

Programmatic buyers can create a filter to match their ads.txt list against the data provided in the OpenRTB bid request.

Rubicon Project forges ahead

According to Adopsinsider, 12.8 percent of publishers (among the Alexa top 10,000 sites that sell advertising) have posted an ads.txt file for their domains — including premium publishers like CBS, Hearst, New York Times, Time Warner and Univision. And that list is rapidly growing. This same report shows that Rubicon Project falls a close second to Google in the list of sellers among those same top 10,000 who have published ads.txt files.

You may see other media reports that claim ads.txt adoption is far smaller, or is stalling. These reports are often based on flawed methodologies. Setting aside the quantitative data published by Adopsinsider, anecdotally we’re hearing a tremendous amount of interest from participants throughout the ecosystem.

To help accelerate adoption, we’ve built a crawler and validation tool that will check for the presence and accuracy of ads.txt files on the domains that monetize on our exchange, and our Revenue Solutions team will be working with sellers to evangelize ads.txt adoption. We expect to see widespread uptake in the coming months as we lay the foundation for real-time filtering that protect all DSPs on the Rubicon Project platform from seeing bid requests for impressions that violate the ads.txt guidelines.

Are you ready to protect your inventory, combat domain spoofing and reduce fraud? If you’re a Rubicon Project publisher you can visit our knowledge base with your platform credentials to learn more about ads.txt or contact the Rubicon Project seller account team to get started.